Lead Roofing Metal Uses & Effects

LEAD ROOFING & FLASHINGCONTENTS: Properties of lead roof materials, examples & photographs of use of lead on roofs, roof flashing, & other roofing applications on buildings; health & environmental effects of use of lead in building roofing systems

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Lead roofing covers, flashings, materials guide:

This article describes and illustrates the use of lead on roofs both as the primary roof covering material and as roof flashings. We include photographs from several countries illustrating the durability of lead roofs. The article series also discusses the health & environmental effects of using lead roofing products and metals.

Shown at page top: lead flashing around chimneys and below a skylight on a fired-clay tile roof in Oslo, Norway. The flexibility of lead makes it an ideal flashing material when the flashing must adapt to curved or irregular surfaces such as the tile roof shown here.

Effects of Lead in Roofing Systems

Shown above and below we see lead roofing atop the Saxon Tower at St. Michaels in Oxford, England in the U.K. Nearly a thousand years old, this is the oldest building in Oxford, dating from at least 1040 A.D., about the time of the Norman Conquest or shortly afterwards. Portions of the tower roof and access stair top are roofed in lead sheeting.

This tower probably served in defence of the north gate of the city of Oxford. The lead roof shown is, of course not quite so old. Its installers Parker and Slater dated their work with the placque shown below: 1765, making this lead roof over 200 years old.

[Click to enlarge any image]

Shown above is a closer view of how this lead roof is assembled. The lead panel edges are folded upwards, abutted together, and the raised seam is covered by the caps that you see as rounded ridges.

Soldered tabs hold the seam cap in place whiile allowing thermal movement among panels without buckling the roof. By the time this roof was installed, lead roofers had perhaps 800 years of experience. Well ... not individually.

We continue with additional examples of lead used in roofing.

Lead Panels Used on Steep Roofs

The steep tower roof shown above, also located in Oxford, is sheathed in lead panels with raised seams.

This lead panel and raised seam approach is quite similar to the Parker/Slater lead use atop the Saxon tower. The seams are lead-soldered. The lead roof panel size was doubtless chosen for ease of working.

Lead Used on Flat & Low-Slope Roofs

Shown above, another Oxford lead roof, larger lead panels cover a low-pitched roof. These larger panels also use the folded, capped standing seam approach to permit movement and avoid leaks in the roof. Shown below is a second low-slope, large lead-panel-covered Oxford roof that is viewed from the top of the Saxon tower - a great place to stand for studying British roofs. Click to enlarge the image and you might also notice the lead-lined eaves-trough gutter at the lower end of this roof.

One of my favourite lead roof photos is this tile roof, also in Oxford and also viewed from the Saxon tower. The roofers have used lead to seal the flat ridge area of a tile roof, lead to provide step flashing and counter flashing against an abutting building masonry wall, and lead flashing also around a small skylight set into the tile roof.

Compelling evidence that lead salts washing down off of the roof, like copper salts in our copper roof photos, manages to dissuade algae, lichens, and fungal growth on the roof tiles themselves. Notice that where more metallic salt run-down is produced by the wider lead roof area a corresponding greater area of light coloured (clean) roof tiles are in view.

Lead Used on Roof Dormers

Above the nearly-flat roof dormer has been covered with a single lead panel that extends up under slates and wraps around the side of the dormer roof sheathing.

Click to enlarge this photo for some other interesting details including lead flashing poorly installed around a plumbing vent - it laps only under the slates above the vent not under the slates at its side; the roofer who installed the dormer flashing took the same "put it on top" approach when flashing the dormer sides to the slate roof.

This detail is characteristic on older buildings into which plumbing was added later: nobody wants to have to pull off and re-install slates to get that plumbing vent in place.

An interesting additional vent, probably for a bathroom exhaust fan, is visible along the hip of this roof.

Lead Used as Roof Flashings

Here lead was used for a beautiful chimney flashing job in Oxford; notice that the step flashing, mostly not visible, is under the roof tiles, the counter flashing seals the tops of the step flashing agasint the chimney, and the bottom of the chimney flashing at its down roof side brings water out to daylight. I'm not so sure about the barely-in-view dormer side flashing in the right of this photo: perhaps that was a different roofer.

Note: we don't know if any the more recent lead flashings shown in this article series are traditional pure lead or newer (and safer) terne-coated metal designed to resemble lead. - Ed.

Lead coated copper (LCC) has become popular as a stain free replacement for copper in large renovation and new construction projects. The Boston Public Health Commission investigated the home of a child with an elevated blood lead level (EBLL) of 11ug/dl. LCC was used on the roof, flashing, and a wall around the ground floor patio.

The condominium interior was free of lead hazards. Sampling found lead dust levels of 224,377 mgs/ft2 wiped from the wall, 36, 441 mg/ft2 on patio, 79,400 mgs/ft2 under the roof drip line, and 11,517 mgs/ft2 at a roof drain to the patio indicating that the LCC was the probable source of the EBLL. Roof areas receiving runoff from the LCC had high lead levels while others had low levels.

This presented a unique problem because LCC is not paint and thus not addressed by the Massachusetts Lead Law.

Using the Massachusetts Public Health Nuisance Laws, an Abatement Order was issued to remove the LCC, but stayed for six months pending study by all parties. The LCC wall was removed, but roof runoff still contaminated the patio and building perimeter.

An encapsulant paint is being investigated to abate lead hazards by covering the LCC roofing. A survey found widespread use of LCC in Boston buildings including hospitals, universities, daycare centers, libraries, office buildings, hotels, and residences.

A Public Health Advisory was issued, the manufacturer removed LCC from the market, and city policy was developed to restrict the use of LCC on city-owned buildings.

Several queries about the effects of lead in roofing systems led us to find this 2002 Q&A offered by NRCA's Jack Robinson, RRC., Quoting:

Question: What are the advantages of using lead or lead-coated copper when installing standing-seam metal roof systems? Are there any government regulations that prohibit or limit the use of lead or lead-coated copper in roof systems? Also, will water that runs off a roof system made from either of these materials pollute groundwater?

Answer: Lead is a soft, common metal with several properties that are useful in roofing applications. Lead-coated copper is copper sheeting coated with lead on one or both sides.

Because lead is malleable, it easily is shaped at relatively low temperatures (70 F [21 C]) without the need for periodic annealing to soften the lead and make it workable. Lead sheets can be manipulated readily with hand tools and formed into complicated shapes. When used for flashings, lead sheets can be formed and adjusted easily in the field to accommodate substrate irregularities.

Lead also is corrosion-resistant. When left exposed, it develops a silver-gray patina that is insoluble in water. Because of the patina's insolubility, rainwater runoff over a weathered lead surface carries little lead or lead-based chemicals. Water runoff from lead surfaces will not cause stains to be deposited on adjacent building materials, such as stone, masonry or cladding.

Lead-coated copper has several advantages when used to form metal roof systems. It provides a durable finish that can be left exposed or painted, and lead coating is more compatible with paint than other metals. Lead-coated copper also is lighter than lead sheets, which reduces roof panels' weight contribution to a roof assembly's dead load. Lead-coated copper, unlike copper, won't stain adjacent materials. It also is easier to form than plain copper because the lead coating acts as a lubricant.

Both lead and lead-coated copper are durable roofing materials with longer estimated service lives than other common steep-slope roof coverings.

In recent years, publicity regarding the toxicity of lead-based paint has been widespread. Many people incorrectly have assumed any exposed lead is a potential health hazard or pollutant.

As previously stated, exposed lead sheets and lead-coated copper are not significantly soluble in water. The same property that prevents lead from depositing stains on adjacent materials also prevents lead or lead-based compounds from being washed off a roof system's surface and carried into groundwater.

Some manufacturers of lead roof coverings have attempted to respond to the public's concerns by providing calculations of lead contamination for specific projects. These calculations take into account a roof system area that will contribute to watershed, estimated average amount of rainfall at a project's location and lead's corrosion rate.

Several of these calculations indicate that the contribution of lead to groundwater attributable to water runoff from a lead roof system is one to two parts per trillion. The level at which the Environmental Protection Agency (EPA) imposes restrictions for lead in drinking water is 15 parts per billion (approximately 15,000 times less than the amount of lead contamination attributable to water runoff from a lead roof system).

According to EPA representatives, there are no regulations that restrict or prohibit the use of lead or lead-coated copper in roof systems. However, should a question arise about a specific project, contact your regional EPA office for additional information. A list of EPA's 10 regional offices can be obtained from EPA's Web site, www.epa.gov.

Additionally, some states may have regulations governing lead usage. To determine whether your state has specific requirements that regulate or prohibit the use of lead or lead-coated copper roof systems, contact your state's environmental protection agency.

Lead Roofing & Flashing Hazard Research

You should be aware there is an Occupational Safety and Health Administration (OSHA) standard that applies to those who work with lead—"The OSHA Guide to Occupational Standard for Lead (General Industry)." For information about this standard, contact Ken Brown, NRCA's director of risk management, at (847) 299-9070, Ext. 262.Web search 09/29/2010, - original source:
www.great-lakes.net/lists/p2tech/2003-08/msg00016.html

During the last six months eight instances of lead poisoning in roofers have been encountered at the Los Angeles County General Hospital. Since a search of the literature fails to reveal an account of such a condition in this occupational group, and since in the light of our investigations the hazard of lead poisoning is a new one in these workers, a report is considered justified.
The most important information concerning these patients is summarized in the accompanying table.

All the patients are males and with but two exceptions are in early adult life. These men have been working as roofers from periods of three months to ten years. All of them give a history of holding the galvanized roofing nails in their mouths while working. None of these give a history of any other exposure to lead. The most striking facts about the entire group are found in the ...

Quek, Udo, and Jürgen Förster. "Trace metals in roof runoff." Water, Air, and Soil Pollution 68, no. 3-4 (1993): 373-389.
Abstract:In this paper we present the concentration of heavy metals (Cd, Cu, Pb, Zn) in runoff from five different roofs (tar felt, pantiles, asbestos cement, Zn sheet, gravel) during two rainfall events. The heavy metal load of roof runoff is assessed and the different processes influencing the fate of heavy metals on roof surfaces and in roof runoff are discussed. The extent of contamination with heavy metals of runoff from different roofing material has the following sequence: zinc sheet>tar felt>pantiles>asbestos cement>gravel. The hazard of infiltration of roof runoff with respect to heavy metals is discussed by comparison with concentrations in rain.

Schill, Jack, and Anastasia Urbanik. "Recognition and Management of Hazardous Building Materials During Demolition Operations." In ASSE Professional Development Conference and Exposition. American Society of Safety Engineers, 2014.

Frequently Asked Questions (FAQs)

Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.

...

Ask a Question or Search InspectApedia

Questions & answers or comments about lead roofing materials & lead flashing.

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

[1] Follansbee Roofing, Follansbee WV 26037, Tel: 800-624-6906, website: www.follansbeeroofing.com and http://www.follansbeeroofing.com/products/TerneII.aspx Quoting Follansbee on TerneII properties:Follansbee Steel is the only manufacturer of a pre-painted or natural Terne roof and is a leading supplier of metal roofs for new and retrofit commercial, institutional, residential and historic preservation projects.

Terne II - Classic Terne-Coated Steel
... is a new and improved version of historic Terne metal, ... Terne II has improved capability for resisting corrosion in all environments ... also has excellent formability, solderability, and affinity for paint ... without compromising mechanical characteristics. It can be used in flatlock, standing seam, vertical wall designs and virtually any other application in which original Terne has been used. It is strong and ductile, having high yield and tensile strengths as well as workability. This new material can easily be formed with conventional roofing tools.

With Terne II roofing, it is advisable to paint the material as soon as conditions permit. Oxide formation is slower than with the original Terne and the wait for proper painting conditions provides substantially less risk. The new material is coated with Follansbee's new ZT® alloy, a combination of zinc and tin. This coating is designed not only as a barrier but also to be anodic to the steel substrate and reduce the potential for oxidation before painting.

The traditional oil-based paints long required on original Terne are not recommended for application on Terne II. Follansbee's Rapidri paint with its faster drying time and ease of application is much superior to the old painting system. The Rapidri acrylic paints are aesthetically pleasing while offering enhanced durability and color retention. ...

Metal Roofing Alliance, E. 4142 Hwy 302, Belfair, WA 98528, Telephone:(360) 275-6164, Customer Support 410-534-6900, Email: support@metalroofing.com,
Website: www.metalroofing.com. Quoting:The Metal Roofing Alliance was formed in 1998 by a small group of forward-thinking metal roofing manufacturers with the main goal of educating consumers about the many benefits of metal roofing. Since our inception, we've shown millions of people just how beautiful, durable and money-saving metal roofing can be for them. Over the years, our membership has grown to include paint companies, material suppliers, industry publications and more. Be sure to take advantage of all of the great resources our members offer.

The Metal Initiative, 4700 W. Lake Ave., Glenview, IL 60025, P:847.375.4785 Website: www.themetalinitiative.com/, Email: Louise Ristau lristau@connect2amc.com Quoting:The Metal Initiative is a coalition of manufacturers, individuals and associations that have come together to provide information on the features and benefits of metal in construction. Carrying its message of metal primarily to the professional building owner community, The Metal Initiative seeks to gather and disseminate useful information for decision-makers.

Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: info@carsondunlop.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.

The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors.Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.

TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & AssociatesSpecial Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.

The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume.

Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.

Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.